I enjoyed it. It has a good balance of making the myths sound exciting, and explaining why they're just myths. I didn't go looking for inaccuracies, but ofc I looked up the cat, so: it says Onzas were proven to exist in 1986.

This is a realistic-sounding text on onzas, saying there's no reason to believe onzas are their own species www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S0327-93832008000100015

And this is the article that says the 1986 onza was a puma, based on it's DNA (pdf) www.nativefishlab.net/library/textpdf/19135.pdf